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Copy 1 



THE EXTRACTION AND SATURATION OF 
50IL5 WITH VOLATILE ANTISEPTICS 



A THESIS 

PRESENTED TO THE FACULTY OF THE GRADUATE SCHOOL 
OF CORNELL UNIVERSITY FOR THE DEGREE OF 

DOCTOR OF PHILOSOPHY 



BY 

JOHANNES PETRUS DU BUISSON 



Reprinted from Soil Science, Vol. Ill, No. 4, April, 1917 



THE EXTRACTION AND SATURATION OF 
SOILS WITH VOLATILE ANTISEPTICS 



A THESIS 

PRESENTED TO THE FACULTY OF THE GRADUATE SCHOOL 
OF CORNELL UNIVERSITY FOR THE DEGREE OF 

DOCTOR OF PHILOSOPHY 



iBxnl*'**"' 



BY 

JOHANNES PETRU5 D\J BU15SON 



Reprinted from Soil Science, Vol. III. No. 4. April, 1917 



b 






THE EXTRACTION AND SATURATION OF SOILS 

WITH VOLATILE ANTISEI'TICS' 

By 

j. p. du buisson 
Introduction 

Thai partial sterilization cjI soils is a factor to be considered in soil 
fertility has l>een demonstrated beyond doulit during the last thirty years. 
Partial sterilization may be effected either by heating the soil or by treat- 
ing it with a volatile, a non-volatile, or a solid antiseptic. However, heat- 
ing soil and treating it with volatile antiseptics are the two methods that 
have especially been studied by investigators up to the present time. The 
effect of heat on soil was first noticed by early bacteriologists. .Since 
then, this phenomenon has been studied variously and extensively. Many 
conflicting theories have been offered as a solution for the cause of these 
beneficial effects. Some have attributed them to a biological, others to a 
chemical or inechanical, change in the soil itself, and still others to all 
three factors combined. 

The present report is limited to the study of volatile antiseptics only. 
The object of this investigation was to determine, if i>ossible, whether 
there is any essential difference in the effect of saturation as cnmi)ared 
with extraction of different soil types with volatile antiseptics. With this 
in view, the effect of both saturation and extraction, on separate saiiiples 
of the same soil types, was studied, in so far as these substances influ- 
enced plant growth, ammonification, nitrification, and the total water- 
soluble salts in the soils used in the experiment. 

A comparison of the effects of saturation and extraction was made 
for the purpose of testing the theory, advanced by Greig-Smith (17), that 
the volatile antiseptics dissolve the "agricere" that covers the surfaces of 
the soil particles and by so doing enables higher plants and also bacteria 
to obtain more nutriment. Extraction with the antiseptics .should remove 
the '"agricere" more completely than mere saturation, and might, there- 
fore, be expected to produce a condition more favorable to both higher 
plants and bacteria. 

*A thesis submitted, to the faculty of the Graduate School of Cornell tJnivcrsity, in partial 
fulfilment of Ihc rcquiri'mcnt* for the dcRrec of Doctor of Philosophy. 
Received for publication \oveml>er 27. 1916. 



354 SOIL SCIENCE 

I. Historical 

1. Increase of Productivity due to Treatment of Soil with 

Volatile Antiseptics 

The first record of an antiseptic treatment of soil seems to be that of 
OberHn (37). After using carbon bisulfide as an insecticide in some of 
his vineyards tliat were attacked by Phylloxera, he noted a marked in- 
crease in the growth of the vines. Girard (15) found beneficial results 
from this antiseptic witli sugar beet. Pagnoul (38) observed the same 
phenomenon with buckwheat and with mustard. His observations 
with mustard are corroborated by Wagner (51). Mach (32) re- 
ported greater yields with beets, oats, and potatoes, after the appH- 
cation of 200 gm. of carbon bisulfide to a square meter of soil. 
Wollny (53) obtained increased results in pot experiments as a 
result of carbon bisulfide treatment. Koch (23) found increased 
growth vv'ith buckwheat and mustard and beneficial results in vine- 
yards. In 1911 the same author (24) reported the following relative 
green weights for buckwheat : untreated soil, 100 ; application of 200 c.c. 
ether, 153; of 500 c.c, 179. Hiltner and Stormer (20) obtained increased 
yields for buckwheat on soil treated with carbon bisulfide. Moritz and 
Scherpe (35) report an increased yield with potatoes and rye with carbon 
bisulfide. Nobbe and Richter (36), treating soil with ether, chloroform, 
carbon bisulfide and benzene, report the following relative dry v/eights: 
118, 114, 122, 122, respectively, against 100 for untreated. Egorov (10) 
noticed higher yields of oats with carbon bisulfide treatment. Darbishire 
and Russell (9) found an increase in the yield of buckwheat and mustard 
on soil treated with chloroform;, carbon bisulfide, ether and toluene. 
Likewise there was an increased yield of turnips on soil with formalin 
as an antiseptic. Russell and Hutchinson (43) obtained greater yields 
with wheat and rye on toluene-treated soil than on mustard soil. Sherpe 
(45) reports an increased yield of rye on soil treated with carbon bisul- 
fide. Emmerrich, Leiningen and Loew (11) noticed a beneficial effect 
with carbon bisulfide on cane seedlings. Stone (48) similarly obtained 
better growth with lettuce after treating the soil with carbon bisulfide. 
Gainey (14), while experimenting with toluol, carbon bisulfide and 
chloroform, found increased yields with oats, wheat, and buckwrheat. 

It is evident from these results that tlie ability of partially sterilized 
soils to yield larger crops is a general one. Furthermore, it holds for all 
the soils studied and for the various volatile antiseptics examined. Ac- 
cording to Russell and Hutchinson (43) this seems to be true for all 
plants except for those of the leguminous order. 

2. The Effect of Partial Sterilization on the Ammonifying and 
Nitrifying Power of the Soil 
Here will be considered some of the investigators who noted the 



DU BUISSON- EFFECT OF VOLATILE A\'TLSEPT1CS 355 

effect of volatile antiseptic on the nitrifying and ammonifying power of 
the soil. The data are very conflicting on this point. Wagner (51) 
found a decrease in nitrification with carbon bisulfide treatment. Coleman 

(8) reported an immediate inhibiting eflfect on nitrate formation on soil 
treated with carbon bisulfide, but after a time found an increase. 

Lipman (27), on the other hand, reports a beneficial effect both for 
ammonification and nitrification. Stomier (49) and Scherpe (45) both 
observed an increase in ammonification but a detrimental effect on nitri- 
fication. The results of tliese two investigators are corroborated by the 
more extensive work done in England, especially by Russell and Hutch- 
inson (43), who found the production of ammonia after partial steriliza- 
tion at first slow, then rapid, and then more or less constant. Goodey 
(16), Hutchinson and MacLennan (21), Buddin (5) and others report 
similar results. 

Laidlaw and Price (26) noted that in partially sterilized soil more 
ammonia was produced but a cessation of the nitrifying process took 
place. On the other hand, Chaudon de Briailles (7), Pagnoul (38), Koch 
(24) and Fred (13) all report that partial sterilization enhanced the 
process of nitrification after a considerable duration of time. Notwith- 
standing the fact that the reported results are somewhat conflicting, 
there appears to be a pronounced indication that the volatile antiseptic 
treatment of the soil inhibits, at least for a time after the treatment, the 
nitrification process. This inhibition is then followed by a marked stimu- 
lation. 

3. The Effect of Volatile Antiseptics upon the Total Water-Soluhle 
Salts in the Soil 
The literature on this subject is very meager. Mo.st of the investi- 
gators have studied the availability of plant-food due to the effect of 
partial sterilization with heat. Koch (23) does not believe that carbon 
bisulfide directly liberates plant nutrient elements, but states that as car- 
bon hisulfiide stimulates plant growth, it is reasonable to expect 
that more plant-food is removed from the soil. Darbishire and Russell 

(9) found tliat soil treated with carbon bisulfide was able to supply the 
plants with 75 per cent more phosphoric acid, 40 per cent more potash 
and 50 per cent more nitrogen dian the untreated soil. Using plants as 
indicators, Russell and Hutchinson (43) showed that more nitrogen, 
phosphorus and potassium were remnvcd from soil treated with carbon 
bisulfide than from the untreated soil. 

The partial sterilization of the soil by heat has been more extensively 
studied. Frank (12), Kruger and Schneidewind (25), Lyon and Bizzell 
(31), Pickering (40), and Stone (48) demonstrated that soluble plant 
and bacterial nutrients have been increased in partially sterilized soil 
with such treatment. As partial sterilization with volatile antiseptics is 



356 W/i. SCIENCE 

analogous in many respects to sterilization with heat, it would seem that 
more plant nutrients should become available when the soil is treated 
than when untreated with such volatile antiseptics. 

4. Methods of Treatiiig the Soil with Volatile Antiseptics and the 
F.jfcct upon Biological Processes 

Various methods have been enij)loyed for treating the soil with vola- 
tile antiseptics. The general method under field conditions seems to 
have been the introduction of the antiseptic by means of holes bored in 
the soil at regular intervals. Mach (32) added 200 gm. of carbon bisul- 
fide per square meter. Koch (23) applied 60 c.c. of carbon bisulfide 
and ether respectively, to 20 kg. of soil. Hiltner and Stormer (20) 
applied 516 gm. of carbon bisulfide to a sc(uare meter of soil as follows: 
three holes were made, each 30 cm. deep, in every square meter of soil; 
the carbon bisulfide was poured into the holes, which were immediately 
filled up with soil ; the plot of soil was afterward spaded over to insure 
equal distribution of the antiseptic; the >^oil was not seeded nor samples 
taken for biological determination, as the case might be, until all odor 
from the antiseptic had disappeared. Koch (24) and Fred (13) used 
similar methods for the different antiseptics, the latter working with pot 
experiments. 

Nobbe and Richter (36) applied to the first set of experiments 62 gm. 
of ether to each pot of 3600 gm. of soil. To the second set having the 
same ciuantity of soil and known as the etlier emulsion treatment, 300 c.c. 
of ether and 300 c.c. of water were added. The soils were then thoroughly 
mi.xed vxitli the antist-ptic. put into air-ticrhl boxes with a smaJl receptacle 
containing ether, for a given time, and then exposed to the free atmos- 
phere. In a third test, hydrogen peroxide was used. A 30 per cent 
solution diluted with 750 c.c. of water was applied to each pot of soil as 
above stated. The soil was thoroughly mixed and was then considered 
ready for the growth of plants. The authors also report experiments 
with ether, carbon bisulfide, chloroform and benzene where the method 
of treatment was identical as under the second set described above. 

Darbishire and Russell (9) added 25 c.c, respectively, of carbon 
bisulfide, chloroform, toluene, ether and benzene to 1 kg. of soil. The 
pots with soil were covered and allowed to stand for a period of one 
week. The soil was then spread open in a thin layer and the antiseptics 
allowed to evaporate. The evaporation took about 3 days. Russell and 
Hutchinson (43) employed a similar method but used only 2 c.c. of 
toluene per kilogram of soil where plants were to be grown. For the 
determination of the ammonifying and nitrifying power of the soil, 40 
gm. of toluene were added to a receptacle holding 8(X) gm. of soil. A 
second series was treated similarly, but the toluene allowed to evaporate 
at the end of 3 days, while in the first series the antiseptic remained in 
the soil during tlie whole period of experimentation. 



DU BUfSSON—EFFECT OF VOLATILE ANTISEPTICS 357 

5. The Relative Effect on Crop Yields of the Different Volatile Antisep- 
tics in the Partial Sterilization of Soils 

Though several investigators have studied different antiseptics, car- 
bon bisulfide has been used to a greater extent than any other. Koch 
(23) reports that better crop yields v^-ere obtained witli carbon bisulfide 
as an antiseptic than with ether under similar conditions. In 1911 the 
same author (24) pointed out an increase of crop yield witii increase of 
quantities of carbon bisulfide and ether used, but not necessarily propor- 
tional to the amount applied. The effectiveness again was in favor of 
carbon bisulfide. 

According to the crop yields reported by Nobbe and RiclUor (36), 
the order of effectiveness of the antiseptics used was as follows : carbon 
bisulfide, benzene, chloroform, and ether. It would seem from the rela- 
tive weights reported for buckwheat by Darbishire and Russell (9) that 
carbon bisulfide is better than chloroform and the latter superior to ether 
as an antiseptic. For mustard tlie following order was observed by the 
same authors: chloroform, benzene, carbon bisulfide, and toluene, with 
an average relative yield of 118 against 100 for the untreated soil. From 
the meager literature available it is apparent that some antiseptics are 
more effective than others. 

6. Suggested Theories in Explanation of the Effect of the Partial 
Sterilisation on Soil Fertility 

A number of views have been advanced to explain the cause of the 
beneficial effect that higher plants and bacterial flora derive from partial 
sterilization of soils by volatile antiseptics. These will be discussed in 
the order of their priority. 

Koch (23) holds that partial sterilization has a direct stimulating 
effect upon the higher and lower forms of plant life in the soil. He is 
not die only investigator to produce data substantiating this veivv. Nobbe 
and Richter (36), Egorov (10), Fred (13) and others are nf the same 
opinion. 

Hiltner and Stormer (20) advanced the so-called indirect selective 
theory of the antiseptics as related to die growdi and activity of bacterial 
flora. They maintain that tlie harmful organisms are suppressed, whereas 
the beneficial bacteria are stimulated by the changes brought about in 
the soil as a result of such treatment. 

In 1909 Russell and Hutchinson (43) announced their protozoa 
theory. These investigators believe that the protozoa in the soil hold in 
check the multiplication of tlie bacteria, especially those of the ammoni- 
fying type. They hold that an antiseptic destroys most of the large 
organisms that prey on the bacteria. The latter, although temporarily 
suppressed by the antiseptic, are later able to multiply unhindered and 
so attain numbers greatly in excess of those found in normal soils. The 
(iii— 27^ 



358 SOIL SCIENCE 

greater nimiber of bacteria is assumed to cause more plant nutrients and 
nutrient elements to be elaborated and, consequently, larger crop yields 
are produced. Fred (13), Sherman (47) and others, however, have 
given data showing that some protozoa are not so detrimental to bacteria 
as Russell and Hutchinson believe. 

I'revious to Russell and Hutchinson's work, the existence of protozoa 
in toil was reported by Celli and Fiocca (6), who isolated 6 species of 
amoebre. Other investigators in England who have reported the presence of 
protozoa in the soil are Goodey (16), Martin (33), and Martin and Lewin 
(34). In Germany, Hiltner (19), Tsujitani (50), Emmerich, Leiningen 
and Loew (11 ), Killer (22) and others have noted the same phenomenon. 
In the United States the presence of such organisms has been observed 
by Gjiiney (14), Lodge and Smith (28), Rahn (41), and Sherman (46, 
47). Peck (39) has observed their presence in Hawaii soil. Loew (29, 
30) reported their presence in the soil of the Alps, in Japan, the Island 
of Borkum and in Porto Rico. 

Bolley (1, 2, 3) considers the parasitic fungi in the soil as the chief 
cause, in many cases, of poor vegetative growth. The effect of the partial 
sterilization is to destroy or check the parasitic fungi and, consequently, 
allow the plant to grow unhampered. 

Greig-Smitli (17) has advanced the "agricere" theory. The agricere 
is considered to be a waxy substance, which covers, as it were, the soil 
particles. When the soil is treated with antiseptics this agricere is de- 
stroyed and conditions are rendered more favorable for the liberation of 
nutrients for plants and bacteria. 

Greig-Smith (17) and Bottomley (4) have proved the presence of 
bacterio-toxins in soil. Greig-Smith foimd them to a greater degree in 
poor than in rich soil. He claims that the toxins check bacterial activity 
in the soil. 

Summary of Literature 

1. Treatment of soil witli volatile antiseptics has a definite beneficial 
effect on plants subsequently grown on such soil. 

2. The ultimate effect of partial sterilization is an increased produc- 
tion of ammonia and nitrates. 

3. Heat sterilization of soil liberates plant nutrients. As the treat- 
ment of soil with volatile antiseptics is somewhat similar in effect to 
heat sterilization, a like phenomenon may probably result. 

4. In general, the application of volatile antiseptics to field soil is 
made in holes bored for that purpose. In greenhouse and laboratory 
experiments the antiseptic either is allowed to volatilize after treatment 
or is left in the soil. 

5. Some volatile antiseptics seem to be more effective sterilizing 
agents than others. 

6. Different theories as to the beneficial effects of volatile antiseptics 
mav be stated as follows : 



DU BUISSOX—EFI-ECT Oh VOLATILE ANTISEPTICS 359 

a. Koch believes that antiseptics have a direct stimulating effect on 
plant and bacterial life. . 

b. Hiltner and Stormer consider the action as a disturbance of the 
equilibrium of the soil flora. 

c. Russell and Hutchinson attribute the beneficial effects of volatile 
antiseptics to the suppression of the soil protozoa, which are considered 
to hamper ammonification. 

d. Bolley considers tlie checking of certain harmful parasitic fungi in 
many cases as the real influence of partial sterilization. 

e. Greig-Smidi believes that the solution of certain waxy material in 
the soil by volatile antiseptics afi^ords conditions for a more ready avail- 
ability of plant nutrients. 

II. Conditions and Methods of Experimental Procedure 

The experimental data embodied in this report were derived from two 
sources: greenhouse studies and laboratory investigations. 

Both parts of the report were carried out in the Soil Technology 
Department of Cornell University, beginning with the spring of 1915 
and continuing through the summer of 1916. 

1. Pots. 

Four classes of receptacles were used for die vegetative part of the 
experiment. ' 

(a) Glazed crockery pots of yi-gallon cai^acity, AY' inches in diame- 
ter and 6 inches deep, holding 2^ kg. of Arf soil. 

(b) Small ordinary unglazed flower pots of 5(X)-gm. capacity, 5 
inches in diameter and 5 inches deep. These were used for the ether- 
treated soils described under Experiment I. 

(c) Unglazed clay flower pots of J^-gallon capacity, 6 inches in 
diameter and 6]/^ inches deep. These pots were used in Experiment XI 
for the growth of the wheat crop, having been previously dipped into 
paraffin in order to cut down evaporation and dift'usion through the sides. 

(d) Glazed crockery pots of 2-gallon capacity', 8 inches in diameter 
and 6 inches deep, each holding about 5 kg. of soil. 

It was noticed that the root systems which developed in the smaller 
pots were too crowded, and to eliminate this imfavorable condition larger 
pots were employed, notwithstanding the fact that greater quantities of 
the volatile solvents were necessarv". 

2. Soils. 

Dunkirk clay loam and Volusia silt loam soils were used. Both 
are typical soils in the vicinity of Cornell ITniversity. The Dunkirk clay 
loam was surface soil obtained from the experimental plots of Caldwell 
Field. The Volusia silt loam was surface soil from the Stevens farm on 
Turkey Hill. 



360 



SOIL SCIENCE 



Unpublished results of bulk analysis for Dunkirk clay loam soil are 
as follows : 

FROM 9 SAMPLES OF TOMPKINS COUNTY SOIL 



C (organic carbon) 

COa 

KaO 

CaO 

MgO 

NaaO 

N 

PA 



1.670 

1.740 
0.430 
0.450 
1.090 
0.186 
0.123 



0.440 
0.260 
2.110 
O.S30 
0.690 
1.280 
0.082 
0.126 



Unpublished results of bulk analysis for Volusia silt loam soil are as 
follows : 

FROM 11 S.\MPLES OF TOMPKINS COUNTY SOIL 





Surface % 


Subsoil % 


C (organ 
COa . . . 


c carbon) 


1.960 
trace 
1.630 
0.270 
0.240 
0.850 
0.169 
0.153 


0.650 


KaO 


1.970 


CaO 


0.240 


MgO 


0.250 


Na«0 


0.960 


N 


0.086 


PaOo 


0.127 



The soil in a majority of cases was obtained in bulk. After being 
allowed to dry, it was reworked in order to get rid of lumps and stones, 
the latter being especially numerous in the Volusia silt loam. The soil 
was then sieved through a 2-mm. sieve, except that used in Experiment I, 
which was passed through a 10-mm. sieve. 

3. Treatment of Soils. 

In order that tlie discussion of the different experiments may be 
easier to follow, and to avoid repetition, a description will be given of 
the various solvents employed witli an explanation of the different terms 
used. 

The organic solvents utilized in this experimentation were alcohol, 
benzene, ether, commercial gasoline, and toluene. 

It will be seen from the experiments which follow that the alcohol 
treatment was applied to both ty^pes of soil on three different occasions. 
Ether, gasoline, and toluene, on the other hand, were each applied twice 
to Dunkirk clay loam soil as a treatment and only once to Volusia silt 
loam. Benzene was applied only in Experiment I to Dunkirk clay loam. 

The treatment in general consisted in extracting and saturating each 
type of soil with the individual solvents. 

(a) Extracted soil. 

By extraction it is to be understood that definite quantities of the 
solvent were applied to definite quantities of soil. The ratio was a 
variable one. In case of alcohol and ether, for example, the ratio was 3 



DU BUISSOK— EFFECT OF VOLATILE ANTISEPTICS 361 

of solvent to 1 of the soil. With gasoline, benzene, and toluene the 
ratio was 4 to 1 . The previously prepared soil was placed in a receptacle 
and the proper amount of solvent added. The soil was thoroughly stirred 
three times a day as long as the extraction lasted, which varied from 1 
day for alcohol, to 8 days for gasoline. At the end of tlie extraction die 
solvent was siphoned off. The soil thus treated was then spread out on 
thick paper in a well ventilated dark room until, as far as could be deter- 
mined by the odor, the solvent had disappeared entirely. The time varied 
also in this case from 3 days for alcohol to 10 days for gasoline. Moisture 
determinations were then made and the soil was ready for experimenta- 
tion. 

(b) Saturated soil. 

Each soil was saturated with the respective solvents during the same 
period as in the extraction above described. The soil was then spread 
out and the solvent allowed to evaporate. The drying continued for tlie 
same length of time as for the extracted soil. Moisture determinations 
were then made and the soil was considered ready for use. 

(c) Untreated soil. 

The soils spoken of as untreated in ihis report are the respective 
soils, which were worked up in the same manner as the portions taken 
for the two treatments just described. The soil was spread out for the 
same period as those described under the treatments above, and after 
moisture determinations were made were ready for use. 

4. Moisture Control. 

The soil used for the vegetative work in the greenhouse was kept at 
30 per cent moisture. The incubated soil was kept at 25 per cent mois- 
ture. Both calculations were on the moisture-free basis. The former 
percentage was considered to be the optimum moisture for plant growth. 
The 25 per cent moisture was used for all the incubated soils on which 
tests were run for nitrification, ammonification and total water-soluble 
salts. This percentage was considered the optimum moisture content for 
organisms. 

5. Incubation. 

To test the ammonifying and nitrifj'ing power of the soil, incubation 
tests were run. These were carried out by placing 100 gm. of air-dried 
soil in S-ounce bottles plugged with cotton. Incubation temperature was 
that of the laboratory. 

6. Methods Used for Determining Nitrates. Ammonia and Total 
Sohihle Salts. 

The methods used for determining nitrates and ammonia were those 
described in Bulletin 31 of the Bureau of Soils of the United States 
Department of Agriculture. 

7. General Plan of Experimentation. 

That the data may be presented in as clear a form as possible, a gen- 
eral plan will be presented first and discussed in detail afterwards. The 



362 



SOIL SCIENCE 



vegetative and laboratory parts of the work were divided up into the 
following separate experiments : 

Vegetative Experiments 
Experiment I. Oats, spring of 1915 (followed by buckwheat of 
Experiment IV, summer of 1915). 

Experiment II. Wheat, sunimer of 1915 (followed by oats of Ex- 
periment V, 1915-1916). 

8. Diagrauiatic Flan of Experimentation'' 



Experiment I 
Direct effect of volatile 
antiseptic on oats. 



Experiment II 
Direct effect of volatile 
iitisepttc on xvheat. 



Experiment III 
Direct effect of volatile 
antiseptic on oats. 



Experiment IV 
Residual effect of volatile 
antiseptic on buckwheat after 
oats (Experiment I). 



Experiment ]'' 
Residual effect of volatile 
antiseptic on oats after 
wheat (Experiment II). 



Experiment VI 
Effect of water-soluble al- 
coholic extract from soil 
treated with volatile antisep- 
tic as in Experiment III 
upon oats in water cultures. 



Experiment VII 
Direct effect of volatile 
antiseptic on tjlie chemical 
condition of the soil treated 
with volatile antiseptic as in 
Experiment II. 



Experiment VIII 
Direct effect of volatile 
antiseptic on the chemical 
condition of the soil treated 
with volatile antiseptic as in 
Experiment III. 



Experiment IX 
Residual effect of volatile 
antiseptic upon the chemical 
condition of the soil after 
oats (of Experiment I) and 
buckwheat (Experiment IV). 



Experiment X 
Residua! effect of volatile 
antiseptic upon the chemical 
condition of the soil after 
wheat (Experiment ID and 
oats (Experiment V). 



Experiment XI 
Physical condition of the 
soil upon certain chemical 
factors. Soil of Experiment 
III studied directly after the 
oats. 



Experiment XI I 
The direct effect of volatile antiseptics upon development of acid in the soil. Soil treated 
exactly as in Experiments I, II and III. 

Experiment III. Oats, spring and summer, 1916. (Soil later studied 
chemically. See Experiment XI.) 

Experiment IV. Buckwheat following oats. (See Experiment I.) 

Experiment V. Oats following wheat. (See Experiment II.) 

Experiment VI. Water culture experiments. 
Laboratory Investigations 

Experiment VII. Soil incubated for 3, 6 and 12 weeks. The soil was 
treated with volatile antiseptics exactly as In Experiment II. 

3 It is to he noted that Experiments I, II and III are comparable, also Experiments IV and V, 
Experiments VII and VIII. and Experiments IX and X. Experiments VI, XI and XII are each 
to be considered separately. 



DU BUISSOK— EFFECT OF VOLATILE ANTISEPTICS 363 

Experiment VIII. Soil incubated for 2, 4 and 6 months. The soil 
received the same treatments with volatile antiseptics as in Experi- 
ment III. 

Experiment IX. Soil incubated and studied chemically after harvest- 
ing the buckwheat of Experiment IV. The buckwheat followed an oats 
crop (Experiment I). 

Experiment X. Soil studied chemically directly from [X>ts after har- 
vesting crop of oats (Experiment V) which followed a crop of wheat 
(Experiment II). 

Experiment XL Soil studied chemically from pots and simultane- 
ously incubated after harvesting a crop of oats (Experiment III). 

Experiment XII. The study of the development of acids in soils 
immediately after the treatment with alcohol as an antiseptic. 
III. Vegetative Experiments 

As outlined in tlie general plan, the exp>erimental part is subdivided 
into different experiments which will be discussed in their numerical 
order. 

Experiment I '^ 

The Effect of Volatile Antiseptics Applied to the Soil upon the 
Following Oat Crop 

Both Volusia silt loam and Dunkirk clay loam soils were extracted 
and saturated with 90 per cent alcohol in this experiment. Furthermore, 
benzene, ether, toluene and gasoline, respectively, were applied to Dun- 
kirk clay loam alone. After the soil was treated as already described, 
2 kg. of soil were weighed out in duplicate, into the J^-gallon glazed 
crockery pots. In case of the ether-treated soils, however, only 500 gm. 
of soil were used in the small flower pots. 

The soils stood in the pots for 8 days before seeding. On April 13, 
1915, all the pots were seeded with oats, 16 seeds to a pot. When the 
plants were 2 inches high, all were removed except eight of uniform size. 
At this time, 300 gm. of clean quartz sand were spread over the surface 
of the soil in each pot. This was to act as a mulch and decrease the 
amount of water lost by evaporation. 

The .seeds in the treated soil in most cases germinated a day, and in 
the case of gasoline from 2 to 3 days, later than the seeds in the untreated 
soil. This, however, was not the case with the seeds in the ether-treated 
soil, the germination period lieing the same as that of the seeds in the un- 
treated soil. 

During the first 4 to 6 weeks of growth, the plants in all the pots with 
treated soil (ether being an exception again) did not show the same 
ainount of growth as the plants in the untreated soil. The saturated soil 
maintained a slight advantage over the extracted soil. From this period 
on, however, there was a marked increase in growth of the plants on the 
treated soils, as can be seen from the dry weight of the plants (Table T), 



364 



SOIL SCIENCE 



which were harvested on July 21, 1915, after the crop had passed the 
blooming stage and was about to ripen. 

Conclusions Regarding Experiment I 

These results indicate a decided benefit to crop growth in favor of 
tlie treated soils. The saturated soils responded better to the treatment 
than extracted soils. This is shown not only by the average data but 
also by every individual treatment. 

The 90 per cent alcoholic antiseptic seems to have affected the crop 
growth most beneficially, ether next, then benzene, and finally, toluene. 
The gasoline antiseptic had a detrimental effect, the extracted treatment 
even more so than the saturated treatment. 

T.\BLE I 

RESULTS OBTAINED WITH OATS GROWN' ON SOILS PREVIOUSLY TREATED WITH 

VOLATILE ANTISEPTICS, EXPRESSED AS AVERAGE DRY WEIGHTS 

(Planted April 13, 1915: harvested July 21, 1915) 



Soil 


Volatile 


Untreated 


Saturated Soil 


Extract 


ed Soil 














Type 


Antiseptic 




Relative 




Relative 




Relative 






gm. 


Weights 


gm. 


Weights 


gm. 


Weights 


VSLi 


Alcohol 


2.50 


100 


2.75 


110 


2.50 


100 


DCL= 


Alcohol 


1.70 


100 


.V15 


185 


2.90 


170 


DCL 


Ether» 


1.05 


100 


1.65 


157 


1.25 


119 


DCL 


Gasoline 


1.75 


100 


1.65 


94 


1.30 


74 


DCL 


Toluene 


1.95 


100 


2.35 


121 


2.20 


113 


DCL 


Benzene 


2.05 


100 


2.65 


129 


2.30 


112 


Grand 
















Average 




l.SO 


100 


2.40 


133 


2.07 


115 


' Volusia silt loam. 












2 Dunkirk clay loam. 












= With 


ther treatment o 


nly 6 plants 


were left ir 


each pot to 


mature. 







All of. the antiseptics lengthened the period for germination except 
ether, which treatment produced no variation from the untreated soil. 

Experiment II 

The Effect of J'olatile Antiseptics Applied to the Soil upon the 

Following Wheat Crop 

This experiment was begim in August, 1915. The organic solvents 
used were alcohol, ether and toluene on both Dunkirk clay loam and 
Volusia silt loam. 

Two-kg. flower pots were used into which were weighed 1800 gm. of 
alcohol and toluene-treated soil, respectively. In the case of the ether 
treatments. 1400 gm. of soil were u^^ed. On September 2. 1915, these 
pots were seeded with Galgalos wheat, 20 seeds to a pot. The young 
plants were later thinned to 10 plants of uniform size. 

The first important consideration here was the germinating power of 
the seeds in these differently treated soils. Invariably, the seeds in the 
imtreated soil germinated 2 or 3 days sooner than on the treated soil and 
showed for the first 3 weeks a distinctly better growth. This was es- 



DU BUISSOX— EFFECT OF VOLATILE ANTISEPTICS 



365 



pecially noticed with the alcohol and the toluene treatments. The ether 
did not show this inhibiting effect. As the growing period progressed, 
the plants on the treated soils gradually improved, and showed a healthier 
color and a more vigorous growth at the end of 5 weeks. 

On account of a bad attack of mildew, to which wheat is especially 
subject when grown in the greenhouse during the summer, this crop had 
to be harvested on October 17, thus growing for only 6 weeks. Although 
these results are not so reliable and conclusive as from plants grown to 
maturity, nevertheless the dry weights shown in Table II show a distinct 
tendency in favor of the treated soil. 

TABLE II 

RESULTS OBT..\IXED WITH WIIE.^T GROWN 0\ SOILS PREVIOUSLY TREATED 

WITH VOLATILE ANTISEPTICS, EXPRESSED AS AVERAGE 

GREEN AND DRY WEIGHTS 



(Planted Septe 



3, 1915; harvested October 17, 1915) 







Untreated So 


1 


Sat 


uratcd S 


oil 


Extracted Soil 






Weigh 


of Dry 




Weight 


of Dry 




Weight of Drv 


Soil 


Volatile 




Matter 




Matter 




Matter 


Type 


Antiseptic 




































Wt. of 




Rela- 


Wt. of 




Rela- 


Wt. of 




Rela- 






Green 


gin. 


tive 


Green 


gm. 


tive 


Green 


gm. 


tive 






Crop 




Wts. 


Crop 




Wts. 


Crop 




Wts. 


DCL 


Alcohol 


3.40 


0.80 


100 


6.15 


1.35 


169 


6.65 


1.45 


181 


VSL 


Alcohol 


5.70 


1.20 


100 


7.20 


1.55 


127 


5.75 


1.35 


112 


DCL 


Ether 


4.60 


0.95 


100 


7.55 


1.37 


144 


9.35 


1.65 


173 


VSL 


Ether 


5.50 


1.20 


100 


7.30 


1.32 


110 


8.65 


1.60 


133 


DCL 


Toluene 


4.60 


0.95 


100 


5.83 


1.25 


131 


5.35 


1.20 


126 


VSL 


Toluene 


5.30 


1.05 


100 


7.45 


1.40 


133 


7.75 


1.40 


133 


Grand 






















Average 




4.85 


1.02 


100 


6.91 


1.37 


135.? 


7.25 


1.44 


143 



Conclusions Regarding Experiment II 
The crop in this experiment also responded with greater yields on 
the treated soils than on the untreated ones. There is a general tendency 
in favor of the extracted treatments, aldiough there are marked excep- 
tions diere, also. The order of effectiveness of the antiseptics according 
to the results are alcohol, ether and toluene, respectively. The Dunkirk 
clay loam in general responded better than Volusia silt loam, except for 
the ether treatment, where the reverse was true. Alcohol and toluene 
retarded germination, while ether seemed to have no influence, either 
stimulating or retarding. 

Experiment HI 

The Effect of Volatile Antiseptics Applied to the Soil vpon the 

Folloiifing Oat Crop 

In tlie previous experiment die largest pots used were 3^-gallon pots. 

The object in Experiment III was to study the various treatments on 

larger quantities of soil. Four kg. of soil were used in 2-gallon pots. 

The Dunkirk clay loam was stock soil which had been kept for 3 years 



366 



SOIL SCIENCE 



in the store-room. The Volusia silt loam was the same as previously 
described. 

Both types of soil were extracted with 70 per cent alcohol. The gaso- 
line treatments on both types of soil were in the ratio of 4 parts of 
gasoline to 1 part of soil. Five and 10 days were allowed, respectively, 
for the evaporation of the alcohol and gasoline. 

The soils, after standing for 6 days in the pots, were seeded to oats 
on March 9, 1916. Twenty-five seeds were planted to a pot. but only fifteen 
of the resulting plants were allowed to grow. The same phenomenon 
was observed as in previous experiments, to wit, that the treatment had 
a retarding effect for the first few weeks of growth. After this period, 
the plants on the alcohol-treated soil began to show a more rapid growth, 
extending until the harvest time, June 1, 1916. The plants were in full 
bloom at harvesting. 

TABLE in 

RESULTS OBTAINED WITH OATS GROWN ON SOILS PREVIOUSLY TREATED WITH 

VOLATILE ANTISEPTICS, EXPRESSED AS AVERAGE GREEN AND DRY WEIGHTS 

(Planted March 9, 1916; harvested June 1 and June 30, 1916) 







Untreated Soil 


Saturated Soil 


Extracted Soil 






Weight of Dry 




Weight of Dry 




Weight of Dry 


Soil 
Type 


Volatile 
Antiseptic 




Matter 




Matter 




Matter 
























Wt of 




Rela- 


Wtof 




Rela- 


Wt. of 




Rela- 






Green 


gni. 


tive 


Green 


gm. 


tive 


Green 


gm. 


tive 






Crop 




Wts. 


Crop 




Wts. 


Crop 




Wts. 


DCL 


Alcohol 


91.90 


16.75 


100 


107.45 


21.20 


120 


133.35 


26.10 


155 


VSL 


Alcohol 


61.25 


10.50 


100 


100.40 


19.70 


187 


91.75 


17.90 170 


DCL 


Gasoline 


32.50 


8.95 


100 


35.75 


8.85 


98 


31.00 


7.05 


79 


VSL 


Gasoline 


72.05 


22.55 


MOO 


66.60 


17.60 


78 


71.15 


23.10 


102 


Grand 






















Avrrage 




64.45 


14.69 


100 


77.55 


16.84 


120.7 


81.81 


18.79 


126.5 



m the alcohol-treated soils were harvested on June 
not harvested until June 30. This is one factor 
I the untreated soil of the Volusia silt loam. The 
listure. The green weights do not show this great 



* It should be remembered that the crops fri 
1, 1916, whereas the gasoline-treated soil was 
that accounts for the difference in weight fro 
kernels were riper and thus had very little m 
difference. 

The gasoline treatment, on the other hand, did not show up die dif- 
ferences as early as the alcohol treatment did. After 2 months' growth, 
the plants on the treated soils still continued poorer than those on the 
untreated soil. About 10 weeks after seeding, the plants began to increase 
in growth on the treated soil. 

It may be noted that on the Dunkirk clay loam, although all the 15 
plants remained alive, only 9 plants grew to full height. It seems that 
for some reason the gasoline treatment had a retarding effect. 

Conclusions Regarding Experiment III 
A very marked increase in plant growth in favor of the alcohol treat- 
ment was noted in this test. The Volusia silt loam saturated yielded 



DU BUISSON— EFFECT OF I'OLATILE ANTISEPTICS 



367 



better than the extracted treatment. Witli the Dunkirk clay loam the 
extracted treatment gave tlie highest yield. The gasoline treatment, as 
in Experiment I, shows no beneficial eft'ect. In most cases it was detri- 
mental. 

Summary of Experiments I, II and III 

1. The antiseptic treatment of soil in pots has a distinctly beneficial 
effect on the vegetative growth of succeeding oat and wheat crops. There 
is a slight advantage in favor of the saturated treatments. 

2. Alcohol gave better results on plant growth than ether, benzene, 
toluene and gasoline, respectively. Gasoline is often harmful in its 
effects, both on ])lant growth and on germination. Ether seems to have 
little or no effect in either direction. 

3. A stimulating influence of volatile antiseptics on plant growth 
occurs for both Dunkirk clay loam and Volusia silt loam, but in different 
degrees. Volusia silt loam, in general, responds the better. 



TABLE IV 

RESULTS OBTAINED WITH BUCKWHEAT GROWN ON SOILS PREVIOUSLY 

TREATED WITH VOLATILE ANTISEPTICS AND CROPPED TO OATS, 

EXPRESSED AS AVERAGE GREEN AND DRY WEIGHTS 

(Planted August 5, 1915; harvested October 2, 1915) 







Untreated Soil 


Saturated Soil 


Extracted Soil 






Weight of Dry 




Weight of Dry 




Weight of Dry 


Soil 


Volatile 




Matter 




M 


atter 




Matter 


Type 


Antiseptic 






























Wt of 




Rela- 


Wtof 




Rela- 


Wt of 




Rela- 






Green 


gm. 


tive 


Green 


gm. 


tive 


Green 


gm. 


tive 






Crop 




Wts. 


Crop 




Wts. 


Crop 




Wts. 


DCL 


Alcohol 


34.25 


7.90 


100 


35.75 


8.10 


102 


32.60 


7.9 


100 


WSL 


Alcohol 


24.50 


6.30 


100 


35.00 


7.40 


117 


33.50 


6.5 


103 


DCL 


Benzene 


34.00 


8.20 


100 


40.50 


9.30 


101 


40.00 


9.3 


113 


DCL 


Toluene 


34,50 


8.40 


100 


44.00 


10.40 


123 


45.50 


10.0 


119 


DCL 


Gasoline 


26.00 


6.45 


100 


24.30 


6.25 


97 


23.25 


5.3 


82 


Grand 






















Average 




30.65 


7.45 


100 


35.91 


8.29 


108 


34.97 


7.8 


104 



'ith the alcohol treatment, there was a set ot 
vere obtained: green weight of crop 15.5 gm. 



* In this experiment on the Volusia silt loam 
soil fresh from the field. The following results 
and dry weight 3.7 gm. 

Experiment IV 

The Effect of Volatile Antiseptics upon the Second Crop (Buckivheat) 

Grown after the Antiseptic Treatment of the Soil — 

Antiseptic: Alcohol, Benzene, Ga^soline and 

Toluene — Crops: Oats and Buckwheat 

The soil from Experiment I was taken from the pots, reworked, and 

the oat roots, as far as possible, removed. The soil was then replaced in 

each corresponding pot. On August 5, 1915, all the pots, except ether 

treatments, which were discarded, were seeded to buckwheat, 15 seeds to 



368 SOIL SCIENCE 

a pot. The young plants were tliinned to 10, when they were 10 inches 
high. 

Observations were made of the growth of these plants. The seeds 
all germinated at tlie same time and the growtli continued uniformly imtil 
about 5 weeks after seeding, when the plants on some of the treated soils 
showed a slightly better growth, as can be observed from the dry weights 
of Table IV. The buck-,vheat was harvested on October 2, 1915. Most 
of the seeds were ripe and some even ready to fall. 

Conclusions Regarding Experiment IV 
A residual eiifect of the antiseptic treatment of soil on plant growth 
is brought out distinctly in this experiment. It is not so marked, how- 
ever, as was the direct influence shown in Experiments I, II and III. 
The saturated treatment again averages better than the extracted. In 
every case, except the benzene treatment, the saturated soil gave the 
higher yields. The gasoline treatment, although better on the saturated 
soil than on the extracted, gave in both cases lower yields than the un- 
treated. If preference is to be given for the effectiveness in increasing 
crop yields, toluene seems to be slightly more effective than the other ' 
antiseptics. Gasoline is distinctly the least efficient. The Volusia silt 
loam soil responded to the treatment better than Dunkirk clay loam, as 
expressed in crop growth. 

Experiment P 

r/ie Effect of J^olatile Antiseptics upon the Second Crop (Oats) Grown 

.■Ifter the Antiseptic Treatment of the Soil — Antiseptics: 

Alcohol, Ether and Toluene — Crops: Wheat and Oats 

The soil after the harvesting of the wheat crop of Experiment II was 

taken out of the flower pots, reworked and transferred to >^-gallon 

glazed earthenware jars. Three hundred gm. of clean quartz sand were 

added to serve as a mulch. The moisture content was then kept constant 

until December 15, 1915, when the pots were seeded with oats. The oats 

were sterilized (52) with calcium hypochlorite powder, 10 gm. in 140 

c.c. of water. Out of 20 seeds planted only 12 plants were left growing. 

A notable effect here was that all of the plants on treated and untreated 

soils made the same progress in growth. This continued to be the case 

for the first two months of the experiment. After this period, however, 

the plants in the treated soil showed a distinct improvement over the 

plants in the untreated soil. Hardly any difference in growth was noticed 

between the saturated and the extracted soils. By the middle of March, 

?> months after seeding, all the plants in the treated soil began to show a 

very healthy dark blue color, in contrast with those on the untreated pots, 

which did not have this vigorous appearance; 

By the beginning of April there was not only a distinct difference in 
growth between the different treatments, but a difference was also ob- 



DU BUISSOX-F.FFF.CT OF VOLATILE ANTISEPTICS 



369 



served between the different types of soil. The Volusia silt loam invari- 
ably showed a better growth than the Dunkirk clay loam. This fact 
becomes easily apparent by a study of the results in dry weights given in 
Table V. In order that a fair comparison should be obtained between 
tlie dift'erent treatments, it was thought best to harvest the oats at this 
stage, although they had just begun to head. 



RESULTS OBT.\I.\ED WITH 0.\TS GROWN' OX SOILS PREVIOUSLY TREATED WITH 

VOL.VTILE ANTISEPTICS A.ND CROPPED TO WHEAT, EXPRESSED 

IN AVERAGE GREEN .\ND DRY WEIGHTS 

(Planted December 15, 1915: harvested April 17, 1916) 







Untreated Soil 


Saturated Soil 


Extracted Soil 






Weight of Dry 




Weight 


of Urv 




Weight 


jf Dry 


Soil 


Volatile 
\ntiseptic 




Matter 




Matter 




Matter 
























Wt. of 




Rela- 


Wt. of 




Rela- 


Wt of 




Rela- 






Green 


gni. 


tive 


Green 


gm. 


tive 


Green 


gni. 


tive 






Crop 




Wts. 


Crop 




Wts. 


Crop 




Wts. 


DCL 


Alcohol 


8.90 


2.35 


100 


29.05 


6.45 


274 


30.65 


6.15 


261 


VSL 


Alcohol 


35.60 


6.80 


100 


44.90 


9.15 


135 


40.95 


8.60 


126 


DCL 


Ether 


8.85 


2.05 


100 


23.20 


4.85 


236 


23.65 


4.45 


217 


VSL 


Ether 


26.50 


5.-)0 


100 


30.10 


5.70 


105 


27.95 


5.60 


104 


DCL 


Toluene 


8.95 


2.15 


100 


20.50 


4.40 


204 


24.45 


4.90 


227 


VSL 


Toluene 


23.70 


5.00 


100 


48.65 


9.50 


190 


39.35 


7.90 


158 


Grand 






















Average 




18.75 


3.79 


100 


32.73 


6.67 


190.6 


31.16 


6.26 


182 



Conclusions Regarding E.\periment V 
The residual effects from the antiseptic treatments on crop growth 
are brought out more markedly in this experiment than in the previous 
one. The saturated treatment again gave higher results than the ex- 
tracted, except on the Dunkirk clay loam treated with toluene. The alccv- 
ho! shows the highest benefit as measured in crop growtli, with toluene 
next and ether last. There is only one exception to this order. The rela- 
tive crop weights indicate a better response for the Dunkirk clay loam 
soil. 

Summary of Experiments IV and V 

1. ;\ residual effect of the antiseptic treatment of soil upon the sec- 
ond crop is distinctly brought out in these experiments. The advantage 
is generally in fa\or of the saturated treatment. 

2. The relative influence of the different antiseptics as measured by 
yields indicates that alcohol is most effective, and gasoline, the least. 

3. The Volusia silt loam in general excels Dunkirk clay loam in its 
response to volatile antiseptics, as measured by the yield of the second 
crop after the antiseptic treatment. "* 



370 SOIL SCIENCE 

Experiment VI 

The Hfi'ect of the Alcoholic Extract of Soils upon Oats Groivn in Water 
Cultures 

The object in this experiment was to study the effect on plant growtli 
of the residue of the alcohohc extract obtained in Experiment III. For 
this purpose the alcoholic residue obtained from recovering the alcohol 
extract of both Dunkirk clay loam and Volusia silt loam was evaporated 
to dryness on water bath. It was then taken up three consecutive times 
with 70 per cent alcohol, digested and filtered each time. Finally the 
residue was taken up with distilled water previously treated with carbon 
black. 

The water-soluble portion of this alcoholic soluble material was then 
determined. From the Dunkirk clay loam soil 0.5 gm. was derived, and 
from the Volusia silt loam soil 1.1 gm., the alcoholic-soluble residue being, 
respectively 2 and 3.1 gm. This water-soluble residue was used in grow- 
ing oats in the following way. Half of this water filtrate of both types of 
soil was added in the proportions of 5, 50 and 100 parts per million, re- 
spectively, to a full nutrient solution of the following composition : 

COMPOSITION OF NUTRIENTS 

Ca(N03)a 2. 70 gm. 

MgSOj 0. 60 gm. 

KCl 0. 75 gm. 

KHaPOi 1 . 50 gm. 

FeSO, 0.05 gm. 

Distilled HjO lO-OO liters 

Full nutrient solutions served as checks to the above. The other half 
of the extract was added in the same proportions as above to carbon- 
black-treated distilled water. Distilled water solutions served as checks 
in this case. Oat seedlings were grown in these solutions for one month, 
all of the solutions being replaced once during this period. Four plants 
as uniform as it was possible to obtain were grown in each 8-ounce bottle. 

Conclusions Regarding Experiment VI 

From the data it seems that a soluble substance has been removed 
from the soil, which in water culture, is detrimental to plant growth. Its 
injurious effect in all cases with one exception was brought out more in 
the presence of ntttrients than with distilled water alone. The toxic effect 
was not apparent in the soil itself as has already been shown in previous 
e.xperiments ; if it were, its influence would have been noticed in the com- 
parison of the saturated and extracted treatments of Experiments I, II 
and III. As this was not the case, the results seem to substantiate the 
work of other investigators in their conclusion that a substance, toxic 
when in water culture, may not be toxic in the soil itself. 



DU BUISSON-EFFECT OF VOLATILE ANTISEPTICS 



371 






H Q 


E 


< y 


K < 




r- Z-. 


fe 


a 




a w 


i;; 


y.oi 


ft 


<o 


S< 




^n 


ili 


^2 

•J Ul 


5 



«? 



^o 



^^ 



= 2 = ■'^ 



372 



SOIL SCIENCE 



IV. Laboratory Investigations 
Experiment VII 
The Effect of Alcohol and Toluene Treatments on Amnionification and 
Nitrification in the Soil and npon the Total Soluble Salts after 
Incitbation for Periods of 3, 6 and 12 Weeks 
The effect of the alcohol and toluene treatments on the ammonifying 
and nitrifying power of the soil and upon the total water-soluble salts 
after periods of 3, 6 and 12 weeks, was first taken up. For this a portion 
of the alcohol and toluene-treated soils described under Experiment II 
was utilized directly after the treatment with the volatile antiseptics. 
Nitrates and total soluble salts were determined from duplicate samples 
of each treatment. Ammonia was determined from other duplicate sam- 
ples. 

TABLE VII 

total WATER-SOLUBLE SALTS AND WATER-SOLUBLE NITROGEN OCCURRING AS 

NITRATES AND AS AMMONIA IN DUNKIRK CLAY LOAM WITHOUT 

TREATMENT AND SUBSEQUENT TO TREATMENT WITH 

ALCOHOL, EXPRESSED AS PARTS PER MILLION 











NITRIC NITROGEN 










Time 


LTntrcated Alcohol Saturated 


Alcoliol Extracted 




Actual 
Amounts 


Relative 
Amounts 


Actual 
Amounts 


Relative 
Amounts 


Actual 
Amounts 


Relative 
Amounts 


After 
After 
After 


3 
6 

12 


weeks 

weeks 

weeks 


S.25 100 
25.60 310 
61.00 739 


Nil 
Nil 
2.3 


Nil 
Nil 
28 


Nil 
Nil 
1.65 


Nil 
Nil 
20 


AMMONIACAL NITROGEN^ 


After 
After 
After 


3 
6 

12 


weeks 

weeks 

weeks 


11.05 100 24.1 
70.00 633 109.3 
16.80 152 65.4 


218 
965 
588 


22.90 
193.10 
94.50 


207 
1748 
855 


TOTAL WATER-SOLUBLE SALTS 


After 
After 
After 


3 
6 

12 


weeks 

weeks 

weeks 


64 
62 

78 


100 
97 
122 


75 117 
72 113 
83 130 


73 
70 
77 


114 
109 
120 



1 By armnoniacal nitrogen is meant ammonia expressed as nitrogen. 

Conclusions Re.garding Experiment VII 
The antiseptic treatment exerts a definite efl^ect on the nitrifying and 
ammonifying processes of the soil. The nitrifying power was practically 
inhibited by tlie alcohol and toluene treatments during the first 6 weeks, but 
at the end of 12 weeks small amounts were found. During the same period, 
there was a gradual increase of ammonia reaching its maximum at the 
end of 6 weeks followed by some depression. 

The difference between the saturated and extracted treatments varied, 
but not to a marked extent. The Dunkirk clay loam soil responded more 



DU BUISSON— EFFECT OF VOLATILE ANTISEPTICS 



373 



TABLE Vlll 

TOTAL WATER-SOLUBLE SALTS AND WATER SOLUBLE NITROGEN OCCURRING AS 

NITRATES AND AS AMMONIA IN VOLUSIA SILT LOAM, WITHOUT 

TREATMENT AND SUBSEQUENT TO TREATMENT WITH 

ALCOHOL. EXPRESSED IN PARTS PER MILLION 



XiTRIC XI 



•■CES 





Untreated Alcohol Saturated 


Alcohol Extracted 


Time 


Actual Relative Actual 
Amounts .\niounts Amounts 


Relative 
Amounts 


Actual 1 Relative 
Amounts i Amounts 


After 3 weeks 

After 6 weeks 

After 12 weeks 


4.0 1 100 Ml 
9.6 1 240 Nil 
44.5 j 1112 1.85 


Nil 
Nil 
46 


Nil 1 Nil 
Nil Nil 
2.2 1 55 



AMMONIACAL NITROGEN 



After 3 


weeks 


22.4 


100 


27.3 


122 


21.5 


96 


After 6 


weeks 


96.2 


429 


109.3 


487 


172.5 


769 


After 12 


weeks 


24.7 


110 


39.6 


177 


44.9 


200 



TOTAL WATER-SOLUBLE SALTS 



After 


3 


weeks . . . 


121 


100 


128 


106 


99 


82 


After 


6 


weeks . . . 


. 1 125 


103 


130 


107 


116 


96 


After 


12 


weeks . . . 


130 


107 


85 


70 


76 


63 



TABLE IX 

TOTAL WATER-SOLUl'.LE S.\L1S AND W.VTKK SOLUBLE NITROGEX 0CCI!RR1N'G AS 

NITRATES AND AS AMMONIA IN DUNKIRK CLAY LOAM WITHOUT 

TREATMENT AND SUBSEQUENT TO TREATMENT WITH 

TOLUENE, EXPRESSED AS PARTS PER MILLION 

OF DRY SOIL 



NITRIC xn"i;(H.;Ex 





Untreated 


Toluene Saturated 


Toluene Extracted 


Time 


Actual 
Amounts 


Relative 
Amounts 


Actual 
.•\mounts 


Relative 
Amounts 


Actual 
Amounts 


Relative 
Amounts 


After 3 weeks 

After 6 weeks 

After 12 weeks 


8.30 
38.75 
59.05 


100 
467 
711 


Nil 

Trace 

70.25 


Nil 
Trace 
845 


Nil 
Nil 
3.20 


Nil 
Nil 
39 



AMMONIACAL NITROGEN 



After 3 weeks 
After 6 weeks 
After 12 weeks 

After 3 weeks 
After 6 weeks 
After 12 weeks 



18.90 
68.60 



100 
363 



25.30 

132.05 

12.35 



134 
698 



TOTAL WATER-SOLUBLE SALTS 



34.90 
132.10 
33.15 



185 
698 
175 



107 
107 



(iii— 28) 



374 



SOIL SCIENCE 



to the treatment than Volusia silt loam. The toluene antiseptic seems not 
quite as effective as the alcohol. The general results compare closely. 

That these data corroborate the results of Russell and Hutchinson 
(4.3) and most other investigators can be seen from the literature, viz: 
that nitrification is inhibited, and ammonification gradually increased for 
a certain time. The latter then gradually decreases or remains constant, 
while the former is later stimulated. 

TABLE X 

TOTAL WATER-SOLUBLE SALTS AND WATER-SOLUBLE NITROGEN OCCURRING AS 

NITRATES AND AS AMMONIA IN VOLUSIA SILT LOAM WITHOUT 

TREATMENT AND SUBSEQUENT TO TREATMENT WITH 

TOLUENE, EXPRESSED IN PARTS PER MILLION 











NITRIC NITROGEN 












Time 


L'ntreated 


Toluene Saturated 


Toluene Extracted 




Actual 
Amounts 


Relative 
Amounts 


Actual 
Amounts 


Relative 
Amounts 


Actual 
Amounts 


Relative 
Amounts 


After 

After 
After 


3 
6 

12 


weeks 

weeks 

weeks 


4.1 
17.2 
48.6 


100 
420 
1180 


Nil 
Trace 
2.6 


Nil 

Trace 

63 


Nil 

Trace 

1.9 


Nil 

Trace 

46 


AMMONIACAL NITROGEN 


After 
After 
After 


3 
6 
12 


weeks 

weeks 

weeks 


20.6 
101.1 
19.4 


100 
49 
94 


25.3 
122.6 
39.7 


124 
610 
193 


26.2 
130.6 
33.7 


127 
660 
164 


TOTAL WATER-SOLUBLE SALTS 


After 
After 
After 


3 
6 
12 


weeks 

weeks 

weeks 


121 
124 
129 


100 
103 
107 


145 
137 
135 


120 
114 
111 


133 
127 
121 


no 

105 
100 



There is a general tendency for the total water-soluble salts to increase 
correspondingly to the duration of incubation. The general influence of 
the treatments with volatile antiseptics seems to be slightly to increase 
water-soluble salts. No definite difference can be noted between differ- 
ent soils or between the two methods of applying the antiseptic. The 
data regarding water-soluble salts are variable. 

Experiment Fill 

The Direct Effect of Alcoliolic and Gasoline Treatments on .■Imnionifica- 

tion and Nitrification in the Soil and upon Total Soluble Salts 

Incnhation for Periods of 2, 4 and 6 Months 

For this investigation, definite quantities were taken of the same soil 

as that used in Experiment III. The incubation periods were 2. 4 and 6 

months, respectively. 

The incubation temperature during this time varied from 18° to 26° 
C. The experiments with the alcohol treatment was begun on January 
26, 1916, whereas with the gasoline-treated soils incubation was started 
on February 22. 



DU BUJSsoK-Brrr.cT of volatile antiseptics 



375 



TAni.lC XI 

TOTAL WATERSOLUULE SALTS AND WATEK-SOlAUiLE NITROGEN OCCURRING AS 

NITRATES AND AS AMMONIA IN DUNKIRK CLAY LOAM WITHOUT 

TREATMENT AND SUBSEQUENT TO TREATMENT WITH 

ALCOHOL, EXPRESSED AS PARTS PER MILLION 



NITRIC NITROGEN 





no 


Untr 


ated 


Alcohol Saturated 


Alcohol Extracted 


Til 


Actual 
y\mounts 


Relative 
.■\muunts 


Actual 
Amounts 


Relative 

Amounts 


Actual 
Amounts 


Relative 
Amounts 


After 2 mc 
After 4 mc 
After 6 mo 


nths 

nths 

nths 


6.70 
50.50 
59.40 


100 

m 

886 


Nil 
Nil 
29.20 


Nil 
Nil 
435 


Nil 
Nil 
46.3 


Nil 
Nil 
691 





AMMONIACAL NITROGEN 








After 2 months 

After 4 months 

After 6 months 


5.75 100 

6.45 112 

Trace Trace 


23.00 
13.40 
1.25 


400 
233 
21.7 


19.3 
8.0 
Trace 


335 

139 

Trace 





TOTAL WATER-SOLUBLE SALTS 






After 2 months 

After 4 months 

After 6 months 


104 
132 
146 


100 
127 
140 


106 

112 
157 


102 
108 
151 


122 
113 
115 


117 

108 
110 



TABLE Xll 

TOTAL WATER-SOLUBLE SALTS AND WATKRSOlAir.l.K NITROGEN OCCURRING AS 

NITRATES AND AS AMMONIA IN VOLUSIA SILT LOAM WITHOUT 

TREATMENT AND SUBSEQUENT TO TREATMENT WITH 

ALCOHOL, EXPRESSED AS PARTS PER MILLION 



NITRIC NITROGEN 





Ur 


treated 


1 Alcohol Saturated 


Alcohol Extracted 


Time 


Actual 
Amounts 


Relative 
Amounts 


1 Actual 
1 .-Xmounts 


Relative 
Amounts 


.\ctual 
Amounts 


Relative 
Amounts 


After 2 months 

After 4 months 

After 6 months 


19.2 
24.8 
60.6 


100 
129 
314 


! Nil 

1 Nil 

4.8 


Nil 
Nil 
25 


Nil 
Nil 
Trace 


Nil 

Nil 

Trace 













AMMONIACAL NITROGEN 










After 


, 


months 


5 


9 


100 


23.8 




403 


23 


8 


403 


After 


4 


months 


Tr 


ice 


Trace 


11.4 




193 


12 


3 


209 


After 


6 


months 


Trace 


Trace 


7.6 




129 


11 





:s6 










TOTAL WATER- 


SOLUBLE ; 


:,ALTS 








After 


2 


months 


170 




100 


78 




46 


72 




43 


After 


4 


months 


168 




99 


72 




4.'i 


79 




46 


After 


6 


months 


194 




114 


88 




52 


79 




46 



376 



SOIL SCIENCE 

TABLE XIII 



TOTAL WATER-SOLUBLE SALTS AND WATER-SOLUBLE NITROGEN OCCURRING AS 

NITRATES AND AS AMMONIA IN DUNKIRK CLAY LOAM WITHOUT 

TREATMENT AND SUBSEQUENT TO TREATMENT WITH 

ALCOHOL. EXPRESSED AS PARTS PER MILLION 



NITRIC NITROGEN 





Untreated 


Gasoline Saturated 


Gasoline Extracted 


Time 


Actual i Relative 
Amounts Amounts 


Actual 
Amounts 


Relative 

Amounts 


Actual 
Amounts 


Relative 
Amounts 


After 2 months 

After 4 months 

After 6 months 


7.50 100 
21.40 285 
24.80 331 


Trace 

8.9 
20.5 


Trace 
119 

273 


Trace 
7.7 
19.2 


Trace 
103 
256 











AMMONIACAL 


NITROGEN 








After 


2 m 


onths .... 


7.47 


100 


15-2 




203 


15-2 


203 


After 


4 ra 


onths 


Trace 


Trace 


Trace 




Trace 


Trace 


Trace 


After 


6 n 


onths .... 


Nil 


Nil 


Nil 




Nil 


Nil 


NU 



TOTAL WATER-SOLUBLE SALTS 



After 2 months 


167 


100 


121 


72 


123 


74 


After 4 months 


136 


81 


137 


82 


123 


74 


After 6 months 


120 


72 


116 


69 


103 


62 



TABLE XIV 

TOTAL WATER-SOLUBLE SALTS AND WATER-SOLUBLE NITROGEN OCCURRING AS 

NITRATES AND AS AMMONIA IN VOLUSIA SILT LOAM WITHOUT 

TREATMENT AND SUBSEQUENT TO TREATMENT WITH 

GASOLINE. EXPRESSED AS PARTS PER MILLION 



NITRIC NITROGEN 





Untreated 


Gasoline Saturated 


Gasoline E.xtracted 


Time 


Actual 
Amounts 


Relative 
Amounts 


Actual 
Amounts 


Relative 
Amounts 


Actual 
Amounts 


Relative 
Amounts 


After 2 months 

After 4 months 

After 6 months 


16.8 
51.1 
15.5 


100 
304 
92 


Trace 
11.3 
198.0 


Trace 
67 
118 


Trace 
18.2 
196.0 


Trace 
108 
118 



AMMONIACAL NITROGEN 



After 2 
After 4 
After 6 



Trace 
Nil 



100 
Trace 



12.8 
Trace 
Nil 



139 
Trace 
Nil 





TOTAL WATER-SOLUBLE SALTS 






After 2 months 

After 4 months . . . . 
After 6 months . . . . 


180 
168 
176 


100 
93 
97 


170 94 
161 89 
166 92 


166 
177 
170 


92 
98 
94 



DU BVISSON-EFFECT OF VOLATILE ANTISEPTICS 



377 



Conclusions Regarding Experiment VIII 
The general results shown by this test verify those of Experiment 
VII. It should be remembered tl\at this experiment ran for a period 
twice as long as the previous one and that certain differences may be at- 
tributed to that fact. 

Nitrification was inhibited for a certain time for the alcohol and gaso- 
line treatments. This influence endured longer for the former than for 
the latter. The ammonifying process must have previously reached its 
maximum point according to the lindings of Ex[)eriment VII, and was 
gradually decreasing. 

As in Experiment \'I!, there is a general tendency for the soluble 
matter to increase with duration of incubation. Xo very defrnite con- 
clusions can be drawn as to the effects from the different antiseptics or 
lo differences between the two soils. 

Experiment IX 
The Effect of Volatile Antiseptics upon Nitrification and Ainmonification 
in the Soil and upon the Total Water-Soluble Salts, the Soil Having 
been Cropped to Oats {Expcrinient I) and to Buckwheat (Ex- 
periment IV) Subsequent to the Antiseptic Treatment 
After harvesting the crop of Experiment IV the soil was taken from 
the pots, reworked and maintained in a loose structural condition dur- 
ing incubation. Tests were made at the beginning and after 14 days for 
nitrates, ammonia and total soluble salts with the results given in Tables 
XV to XIX. 

TABLE XV 
TOT.\L WATER-SOLUBLE SALTS AND WATER-SOLUBLE NITROGEN OCCURRING 
AS NITRATE AND AS AMMONIA IN DUNKIRK CLAY LOAM PREVIOUSLY 
TRE.\TED WITH ALCOHOL AND CROPPED TO OATS, AND THEN TO BUCK- 
WHEAT, JUST PRIOR TO THE TESTS, EXPRESSED AS P.\RTS PER MILLION 



NITRIC NITROGEN 





LTntreated 


Alcohol Saturated 1 Alcohol Extracted 


Time 


.•\ctual 
Amounts 


Relative 
Amounts 


Actual 
.\mounts 


Relative Actual 
Amounts Amounts 


Relative 

Amounts 


A* bepinninR 

After 14 days 


4.50 
17.30 


100 
384 


14.2 
17.1 


316 3.9 
380 20.9 


87 
464 



AMMONIACAL NITROGEN 



At beginning 
-Mter 14 days 



17.95 100 

9.80 55 



4.2 
4.3 



TOTAL WATER- SOLUBLE SALTS 



At beginning 
After 14 days 



378 



SOIL SCIENCE 



TABLE XVI 
TOTAL WATER-SOLUBLE SALTS AND WATER-SOLUBLE NITROGEN OCCUR^^^^^^ 

NITRATES AND AS AMMONIA IN VOLUSIA SILT LOAM PREVOUSL\ TREATED 
WITH ALCOHOL AND CROrPED TO OATS AND THEN TO BUCKWHEAT JUST 
PRIOR TO THE TESTS, EXPRESSED AS PARTS PER MILLION 









NITRIC NITROGEN 










Time 


Untreated 


Alcohol Saturated 


Alcohol Extracted 




Actual 
Amounts 


Relative 
Amounts 


Actual Relative 
Amounts Amounts 


Actual 
Amounts 


Relative 
Amounts 


At begin 
After 14 


ning 

days 


3.9 

7.5 


100 
192 


7.2 185 
18.7 480 


9.4 
22.2 


241 
570 






AMMONIACAL NITROGEN 






At begin 
After 14 


ning 

days 


4.3 
10.3 


100 
240 


5.7 
8.7 


132 
202 


12.9 
7.3 


300 
170 


TOTAL WATER-SOLUBLE SALTS 


At begin 
After 14 


ning 

days 


52 
64 


100 
123 


68 
102 


131 
196 


70 
94 


135 
181 



TABLE XVII 

TOTAL WATER-SOLUBLE SALTS AND WATER-SOLUBLE NITROGEN OCCURRING AS 
NITRATES AND AS AMMONIA IN DUNKIRK CLAY LOAM PREVIOUSLY 
TREATED WITH TOLUENE AND CROPPED TO OATS AND THEN TO BUCK- 
WHEAT JUST PRIOR TO TESTS, EXPRESSED AS PARTS PER MILLION 

NITRIC NITROGEN 





LIntreated 


Toluene Saturated Toluene Extracted 


Time 


Actual 
Amounts 


Relative 
Amounts 


Actual 
Amounts 


Relative 
Amounts 


Actual 
Amounts 


Relative 

Amounts 


At beginning 

After 14 days 


7.0 
10.8 


100 
154 


15.7 
14.9 


224 
213 


16.80 
16.20 


240 
231 



At beginning 
After 14 days 



AMMONIACAL NITROGEN 



TOTAL WATER-SOLUBLE SALTS 



At beginning . 
After 14 davs 



227 
231 



DU BUISSON—El-l-ECT OF VOLATILE ANTISEPTICS 



379 



TABI.K XVIII 



TOTAL WATER-SOLUBLE SALTS AND WATER-SOLUBLE NITROGEN OCCURRING AS 
NITRATES AND AS AMMONIA IN DUNKIRK CLAY LOAM PREVIOUSLY 
TREATED WITH BENZENE AND CROPPED TO OATS AND THEN TO BUCK- 
WHEAT JUST PRIOR TO THE TESTS, EXPRESSED AS PARTS PER MILLION 







NITRIC NITROGEN 










Untreated 1 Benzene Saturated 


Benzene Extracted 


Time 


Actual 
Amounts 


Relative 
Amounts 


Actual 
Amounts 


Relative 
Amounts 


Actual 
Amounts 


Relative 

Amounts 


At beginning 

After 14 days 


5.9 
8.6 


100 
146 


6.0 

14.0 


102 
237 


6.20 
10.05 


105 
169 


AMMONIACAL NITROGEN 


At beginning 

After 14 days 


6.5 
Trace 


100 5.1 
Trace 8 . 4 


78 
129 


3.10 
11.70 


48 

180 


TOTAL WATER SOLUBLE SALTS 


At beginning 

After 14 days 


130 

134 


100 
113 


144 
129 


122 
109 


136 
151 


115 
128 



TABLE XIX 



TOTAL WATER-SOLUBLE SALTS AND WATER SOLUBLE NITROGEN OCCURRING AS 
NITRATES AND AS AMMONIA IN DUNKIRK CLAY LOAM PREVIOUSLY 
TREATED WITH GASOLINE AND CROPPED TO OATS AND THEN TO BUCK- 
WHEAT JUST PRIOR TO THE TESTS. EXPRESSED AS PARTS PER MILLION 



NITRIC NITROGEN 





L^ntreated 


Gasoline Saturated Gasoline Extracted 


Time 


Actual 
Amounts 


Relative 

Amounts 


Actual 
-Amounts 


Relative Actual 

Amounts .Amounts 


Relative 
Amounts 


At hegrinning 

After 14 days 


17.80 
17.80 


100 
100 


12.80 
23.50 


72 12.80 
132 24.80 


72 
139 



AMMONIACAL NITROGEN 



At beginning . 
After 14 days 



TOTAL WATER-SOLUBLE SALTS 



At beginning 
After 14 days 



100 
119 



380 



SOIL SCIENCE 



Conclusions Regarding Experiment IX 
The data of tliis experiment indicate that the residual effect of the 
antiseptics is very low, a condition which should be expected after so long 
a period. Between the saturated and extracted treatments no marked 
difference is found, either as to nitrification or ammonification. There 
was a general tendency for a decrease in ammonification the longer the 
incubation was carried on. 

The marked difference previously observed between tlie two types of 
soil from the direct treatment already discussed were lacking. The total 
soluble salts either remained constant or showed a tendency to increase 
with incubation. 

Experiment X 
The Effect of J^olatilc Antiseptics upon Nitrification and Ainmonificathn 
in the Soil and upon the Total Water-Soluble Salts, the Soil Having 
hern Cropped to Wheat {Experiment II) and to Oats (Experi- 
ment F) Subsequent to the Antiseptic Treatment 
In Experiment V it has been stated that one pot of each soil was kept 
for chemical study after harvesting the oats which followed the wheat of 
Experiment II. This study was carried out by keeping these pots in the 
laboratory and making determinations for nitrates, ammonia and total 
soluble salts at the beginning, after 20 days and finally, at tlie end of 60 
days. .Samples were taken from these pots with a cork borer of 2 cm. 
diameter. The holes thus made were filled up with clean sand and the 
moisture content kept constantly at 25 per cent. 

TABLE XX 
TOTAL WATER.SOLUBLK SALT.S AND WATER-SOLUBLE NITROGEN OCCURRING AS 
NITRATES AND AS AMMONIA IN DUNKIRK CLAY LOAM PREVIOUSLY 
TREATED WITH ALCOHOL AND CROPPED TO WHEAT AND THEN TO OATS 
JUST PRIOR TO THE TESTS, EXPRESSED AS PARTS PER MILLION 



NITRIC NITROGEN 





Untreated 


Alcohol Saturated Alcohol Extracted 


Time 


Actual 
Amoimts 


Relative 
Amounts 


Actual Relative Actual j Relative 
.Amounts Amounts Amounts i Amounts 


At beginning 

After 20 days 

After 60 days 


Nil 
Nil 
Nil 


Nil 
Nil 
Nil 


Nil Nil Nil Nil 
Nil Nil Nil Nil 
Nil Nil Nil Nil 



AMMONIACAL NITROGEN 



At beginning . 
After 20 days 
After 60 days 

At beginning . 
After 20 days 
After 60 days 



TOTAL WATER-SOLUBLE SALTS 



122 
109 
109 



DU BUISSON— EFFECT OF VOLATILE ANTISEPTICS 



381 



TAISLE XXI 

TOTAL WATER-SOLUBLE SALTS AND WATER-SOLUBLE NITROGEN OCCURRING AS 
NITRATES AND AS AMMONIA IX VOLUSIA SILT LOAM PREVIOUSLY 
TREATED WITH ALCOHOL AND CROPPED TO WHEAT AND THEN TO OATS 
JUST PRIOR TO THE TESTS, EXPRESSED AS PARTS PER MILLION 



NITRIC NITROGEN 





Untr 


cated 


Alcohol Saturated 


Alcohol Extracted 


Time 


Actual 
Amounts 


Relative 
Amounts 


Actual Relative 
Amounts Amounts 


Actual 
Amounts 


Relative 
Amounts 


At beginning 

After 20 days 

After 60 days 


Nil 
Nil 
Nil 


Nil 
Nil 
Nil 


Nil Nil 
Nil Nil 

Nil 1 Nil 


Nil 

Nil 
Nil 


Nil 

Nil 
Nil 



At beginning . 
After 20 days 
After 60 days 



AMMONIACAL NITROGEN 


At beginning 

After 20 days 

After 60 days 


5.2 100 5.4 

5.3 102 ' 5.2 
Nil Nil Nil 


104 
100 
Nil 


5.5 
5.3 
Nil 


106 
102 
Nil 


TOTAL WATER-SOLUBLE SALTS 



100 
107 



TABLE XXII 

TOTAL WATER-SOLUBLE SALTS AND WATER-SOLUBLE NITROGEN OCCURRING AS 
NITRATES AND AS AMMONIA IN DUNKIRK CLAY LOAM PREVIOUSLY 
TREATED WITH ETHER AND CROPPED TO WHEAT AND THEN TO OATS 
JUST PRIOR TO THE TESTS, EXPRESSED AS PARTS PER MILLION 



NITRIC NITROGEN 



Ether Saturated 



Ether Extracted 



Actual 
Amounts 



Relative 
Amounts 



Actual 
Amounts 



Relative 
Amounts 



Actual 
Amounts 



Relatire 
Amount* 



At beginning 
After 20 days 
After 60 days 

At beginning 
After 20 days 
After 60 days 

At beginning 
After 20 days 
After 60 days 



AMMONIACAL NITROGEN 



2.6 
5.4 



142 
Nil 



TOTAL WATER-SOLUBLE SALTS 



100 
112 



112 
139 
197 



382 



SOIL SCIENCE 

TABLE XXIIl 



TOTAL WATER-SOLUBLE SALTS AND WATER-SOLUBLE NITROGEN OCCURRING AS 
NITRATES AND AS AMMONIA IN VOLUSIA SILT LOAM PREVIOUSLY 
TREATED WITH ETHER AND CROPPED TO WHEAT AND THEN TO OATS 
JUST PRIOR TO THE TESTS, EXPRESSED AS PARTS PER MILLION 



NITRIC NITROGEN 





Untreated 


Ether Saturated 


Ether Extracted 


Time 


Actual 
Amounts 


Relative 
Amounts 


Actual 
Amounts 


Relative 
Amounts 


Actual Relative 
Amounts Amounts 


At beginning 

After 20 days 

After 60 days 


Nil 
Nil 
Nil 


Nil 
Nil 
Nil 


Nil 
Nil 
Nil 


Nil 
Nil 
Nil 


Nil Nil 
Nil Nil 
Nil Nil 



AMMONIACAL NITROGEN 






At beginning 5.42 100 

After 20 days 5.56 103 

After 60 days Nil Nil 


2.63 
5.46 
Nil 


48 2.57 47 
101 2.93 54 
Nil Nil Nil 


TOTAL WATER-SOLUBLE SALTS 


At beginning 47 100 

After 20 days 47 100 

After 60 days 39 83 


45 
41 
72 


96 

87 
153 


46 
43 
60 


98 
91 
128 



TABLE XXrV 

TOTAL W.VTER-SOLUBLE SALTS AND WATER-SOLUBLE NITROGEN OCCURRING AS 
NITRATES AND AS AMMONIA IN DUNKIRK CLAY LOAM PREVIOUSLY 
TREATED WITH TOLUENE AND CROPPED TO WHEAT AND THEN TO OATS 
JUST PRIOR TO THE TESTS, EXPRESSED AS PARTS PER MILLION 



NITRIC NITROGEN 





Untreated 


Toluene Saturated 


Toluene Extracted 


Time 


.\ctual 
Amounts 


Relative 
Amounts 


Actual 
Amounts 


Relative 
Amounts 


Actual 
Amounts 


Relative 
Amounts 


At beginning 

After 20 days 

After 60 days 


Nil 
Nil 
Nil 


Nil 

Nil 
Nil 


Nil 

Nil 
Nil 


Nil 
Nil 
Nil 


Nil 
Nil 

Nil 


Nil 

Nil 
Nil 



AMMONIACAL NITROGEN 



At beginning . 
After 20 days 
After 60 days 

At beginning . 
After 20 days 
After 60 days 



144 
147 
Nil 



TOTAL WATER-SOLUBLE SALTS 



nU RUISSOX— EFFECT OF VOLATILE ANTISEPTICS 



383 



Following the determinations tabulated above, the soils were taken 
from the pots, reworked and maintained in loose structural condition 
during tlie incubation tests. After 20 days determinations were made 
for nitrates, ammonia and total water-soluble salts. The results there- 
from are not reported in tabular form. No nitrates were found in any 
of the different treatments, nor was any ammonia found with toluene 
treatment in cither type of soil. In case of the alcohol and ether treat- 
ments traces of ammonia were found. The total soluble salts hardly 
varied from the determinations reported at the end of 60 days on the 
soil as it stood in the pots. 

TABLE .\.XV 

TOTAL WATKRSOLUBLK .SALT.S AND WATKRSOLUBLE NITROGKN OCCURRING AS 
NITRATES AND AS AM.MONIA IN VOLUSIA SILT LOAM PREVIOUSLY 
TREATED WITH TOUIENE AND CROPPED TO WHEAT .\ND THEN TO OATS 
JUST PRIOR TO THE TESTS, EXPRESSED AS PARTS PER MILLION 



NITRIC NITROGEN 





Untreated 


Toluene Saturated 


Toluene Extracted 


Time 


Actual 
Amounts 


Relative 
.^mounts 


.\ctual 
Amounts 


Relative 
Amounts 


Actual Relative 
Amounts Amounts 


At beginning 

After 20 days 

.^fter 60 days 


Nil 
Nil 
Nil 


Nil 
Nil 
Nil 


Nil 
Nil 
Nil 


Nil 
Nil 
Nil 


Nil Nil 
Ni! Nil 
Nil Nil 



AMMONIACAL NITROGEN 



At beginning . 
After 20 days 
After 60 days 

At beginning . 
After 20 days 
After 60 days 



100 
Nil 



TOTAL W.\TER-SOLUBLE SALTS 



100 
100 



106 
110 



Conclusions Regarding Experiment X 
.\s in b'xperimeiit IX, the chemical results indicate little difference 
between the residual saturated or extracted treatments with volatile anti- 
septics. The results from the treatments by the two methods are very 
similar to those obtained with the untreated soil. This holds true for 
both nitrification and ammonification. The period of incubation did not 
alter either the nitrifying or the ammonifying results. In Tables XXII 
and XXIII there is a slight tendency during the first two weeks towards 
an increase in ammonification with ether as the antiseptic. This was in- 
hibited, however, at the end of 60 days. The total water-soluble salts 
did not materially change during the process of incubation. No residual 
effect, of the volatile antiseptics, developed in either soil tj'pe. 



384 



SOIL SCIENCE 



Experiment XI 
Effect of tlie Physical Condition of Soil Cropped to Oats {in Experiment 
III), Subsequent to a Treatment with Volatile Antiseptics, upon 
Total Soluble Salts and upon Water-Soluble Nitrogen 
Occurring as Nitrates and Ammonia 
In order to determine what effect the physical condition of tlie soil 
would have upon the nitrifying and ammonifying power of the soil, the 
following test was carried out. Of the duplicate treatments of each type 
of soil after harvesting the crop of Experiment III, one pot was main- 
tained undisturbed and determinations made at die beginning, after 21 
days and after 35 days, for gasoline-treated soils, and after 21 and 60 
days for alcohol-treated soils. The duplicate pot of soil in each case was 
reworked and maintained in good tilth for the same period of time as 
above, and is designated in the tables as incubated soil. 

TABLE XXVI 
EFFECT OF PHYSICAL CONDITION OF SOIL ON. TOTAL WATER-SOLUBLE SALTS 
AND UPON WATER-SOLUBLE NITROGEN OCCURRING AS NITRATES AND AS 
AMMONIA IN DUNKIRK CLAY LOAM CROPPED TO OATS (EXPERIMENT III) 
AND SUBSEQUENT TO A TREATMENT WITH ALCOHOL, EXPRESSED AS 
PARTS PER MILLION 



NITRIC NITROGEN 





I'litrcded Alcohol Saturated Alcohol Extracted 


Time 


.\Ltii;:l 
Amounts 

Puts 


Actual 1 Actual | Actual Actual 
Amounts 1 Amounts | Amounts Amounts 

in Soil 1 in in Soil in 
Incubated Pots Incubated Pots 


Actual 
Amounts 

in Soil 
Incubated 


At beginning 

After 21 days 

After 60 days 


Nil 
0.99 
14.20 


Nil Nil Nil Nil 
2.4 Trace 0.54 | Trace 
36.7 2.1 4.60 1 3.7 


Nil 
0.64 
5.40 



AMMONIACAL NITROGEN 



At beginning . 
.After 21 days 
After 60 days 




TOTAL WATERSOLUBLE SALTS 



At beginning . 
After 21 days 
After 60 days 



146 
120 



Conclusions Regarding Experiment XI 
These data indicate that the effect of the antiseptics has been inhibi- 
tive. At the beginning of incubation, regardless of differences of soil or 
in treatment, there was no difference to be seen in the nitrifying or 
ammonifying processes of the soil. The nitrates and ammonia may have 
been entirely used up by the plants. Even between the two types of soil 
there was no marked difference to be noticed. The Volusia silt loam 
shows a higher yield of nitrates for gasoline treatment. The main point 



PU BIJISSOX— EFFECT OF VOLATILE ANTISEPTICS 



385 



TABLK XXVll 

KFFECT OK PHYSICAL COXDITIOX OK SOIL OX TOTAL WATER-SOLUBLE SALTS 
AND UPON WATER-SOLUBLE NITROGEN OCCURRING AS NITRATES AXD AS 
AMMONIA IN VOLUSIA SILT LOAM CROPPED TO OATS (EXPERIMENT III) 
AND SUBSEQUENT TO A TREATMENT WITH ALCOHOL, EXPRESSED AS 
PARTS PER MILLION 



NITRIC NITROGEN 





Untr 


eatcd j Alcohol Saturated j Alcohol Extracted 


•|im<: 


Actual 
Amounts 

Pots 


Actual Actual 
Amounts \ Amounts 

in Soil 1 in 
Incubated Pots 


Actual Actual Actual 
Amounts Amounts Amounts 

in Soil in in Soil 
Incubated Pots Incubated 


At beginning 

After 21 days 

After 60 days 


Nil 
6.6 
13.3 


Nil Nil 
7 . 5 Trace 
13.2 1.5 


Nil Nil 
1.1 Trace 
3.0 2.8 


Nil 
1.6 
3.7 



AMMONIACAL NITROGEN 



At beginning 
After 21 days 
After 60 days 

At beginning 
After 21 days 
After 60 days 




TOTAL WATER-SOLURLE S.\LTS 




TABLE XXVIII 

EFFECT OF PHYSICAL CONDITION OF SOIL ON TOTAL WATER-SOLUBLE SALTS 
AND UPON WATER SOLUBLE NITROGEN OCCURRING AS NITRATES AND AS 
AMMONIA IN DUNKIRK CLAY LOAM CROPPED TO OATS (EXPERIMENT III) 
AND SUBSEQUENT TO A TREATMENT WITH GASOLINE, EXPRESSED AS 
PARTS PER MILLION 



NITRIC NITROGEN 





I'ntreated 


Gasoline Saturated 


Gasoline Extracted 


Time 


Actual 
Amounts 

Pots 


Actual 
Amounts 

in Soil 
Incubated 


Actual 
Amounts 

Pots 


Actual 
Amounts 

in Soil 
Incubated 


Actual Actual 
Amounts Amounts 
in in Soil 
Pots Incubated 


At beginning 

After 21 days 

After 35 days 


Trace 
Trace 
2.4 


Trace 

3.5 
8.0 


Nil 
Trace 
2.6 


Nil 
3.5 
7.6 


Nil Nil 
Trace 3.6 
3.0 8.5 



AMMONIACAL NITROGEN 



At beginning . 
After 21 days 
After 35 days 

At beginning . 
After 21 days 
After 35 days 



TOTAL WATER-SOLUBLE SALTS 



386 



SOIL SCIENCE 



to be brought out in this experiment is that die physical condition of the 
soil can be largely eliminated as a factor influencing the nitrifying and 
ammonifying processes of the soil for the conditions under which these 
experiments were carried out. The Volusia silt loam treated with gaso- 
line shows greater increase in the nitrifying power of the soil than the 
corresponding alcohol series. 

TABLE XXIX 

EFl'ECr OF PHYSICAL CONDITION OF SOIL ON TOTAL WATER-SOLUBLE SALTS 
AND UPON WATER-SOLUBLE NITROGEN OCCURRING AS NITRATES AND AS 
AMMONIA IN VOLUSIA SILT LOAM CROPPED TO OATS (EXPERIMENT III) 
AND SUBSEQUENT TO A TREATMENT WITH GASOLINE, EXPRESSED AS 
PARTS PER MILLION 



NITRIC NITROGEN 





Untre.nted 


Gasoline Saturated 


Gasoline Extracted 


Time 


Actual 
AmoiMits 

Pots 


Actual 
Amounts 

in Soil 
Incubated 


Actual 
Amounts 

Pots 


Actual 
Amounts 

in Soil 
Incubated 


Actual 
Amounts 

Pots 


Actual 
Amounts 

in Soil 
Incubated 


At beginning 

After 21 days 

After 35 days 


2.4 
3.7 
7.9 


2.4 
19.0 
22.7 


2.8 
11.3 
25.3 


2.8 
18.5 
36.2 


Nil 

12.0 

30.0 


Nil 

19.3 

39.5 



AMMONIACAL NITROGEN 



At beginning . 
After 21 days 
After 35 days 

At beginning . 
After 21 days 
After 35 days 



TOTAL WATER-SOLUBLE SALTS 



100 
106 



Experiment XII 
Development of Acid in Soil Due to the Action of .llcohol 

The idea was suggested that volatile antiseptics applied to the soil 
might be oxidized with the formation of an acid. If an acid were formed, 
it might not only have a depressing effect on the soil organisms but might 
liberate certain mineral elements in the soil. The effects of volatile anti- 
septics upon crop growth and bacterial action might thus at least par- 
tially be accounted for. In order to test this out, tlie following experi- 
ment was performed. 

About 250 gm. of both Dunkirk clay loam and Volusia silt loam were 
used, separate samples being placed in 2-inch glass cylinders. The vari- 
ous samples were then saturated over night with distilled water, potassium 
nitrate and 70 per cent alcohol, respectively. The next morning, more 
water was added to the soils saturated with distilled water and potassium 
nitrate until about 150 c.c. of solution had percolated through. The 



DU BUISSOK-El-l-ECT OF VOLATILE ANTISEPTICS 



387 



alcohol-saturated soil was treated similarly but with the concentration of 
alcohol previously used. After die initial percolations were obtained, the 
soils were spread out for 3 days and allowed to dry. They were tlien 
percolated again as already described. This second percolate obtained 
from tlie soils is designated in tlie table of data as "after aeration." 

Fifty-c.c. quantities of the various percolates were diluted to 200 c.c. 
with CO.-free water and titrated against N/10 NaOH. The results 
reported in Table XXX are the average of duplicate determinations. 
TABLE x.\.\ 



ACTUAL ASD RELATIVE 


.■\MOUNTS OF ACID DEVELOPED Ii\ 
TRE.\TMENT OF ALCOHOL 


SOIL DUE TO 


Type 

Soil 


Percolate 


Water 


Potassiur 


n -Nitrate 


Alcohol 


.■\ctual 
Amts. 


Rel. 
Amts. 


Actual 
.Amts. 


Kel. 
.■\nits. 


,\ctual 
Amts. 


Rel. 
Amts. 


DCL 
DCL 

VSL 
VSL 


Inilial percolation 
After aeration 
Initial percolation 
After aeration 


0.15 
0.20 
0.20 
0.25 


100 
100 
100 
100 


0.65 
0.70 
5.50 
0.65 


430 
350 
2750 
260 


0.60 
0.70 
0.70 
0.75 


400 
350 
350 
300 



Conclusions Regarding Experiment XII 

In the case of Dunkirk clay loam, a soil neutral or very slightly acid, 
tlie relative amounts of acid as developed by KNO., and alcohol in the 
first percolation are about the same. Witli the Volusia silt loam, how- 
ever, a soil intensely acid, the KNO3 in the case of the initial percolate 
generates an acidity several times that of distilled water. The alcohol, 
on the other hand, exhibits about the same results as when percolated 
through the Dunkirk clay loam. It seems evident that the acidity devel- 
oped by the alcohol is about at its maximum in both cases. 

The second percolate of the soils shows an acidity for the alcohol in 
both cases lower than in the initial trial. If the antiseptic forms an acid 
to any degree, the drying action should be expected to augment the acid 
condition. 

From the fact, therefore, (a) that the alcohol reacted about the same 
for both soils, (b) that the second percolate showed an actual lowering 
acidity in spite of the aeration of the soil, and (c) that tlie aeration of 
the alcohol-treated soils was so low as probably to l>e within experimental 
error, it seems impossible to conceive that the development of acids by 
the action of the antiseptic could be an im]K)rtant factor in influencing 
plant and bacterial action, especially in the magnitude already described 
in the preceding experiments. 

V. .Summary 

1. The application of volatile antiseptics to the soils used in tliis in- 
vestigation gave beneficial results on tlie crops subsequently grown 
thereon. 



38g SOIL SCIENCE 

2. A beneficial, residual effect is observed for the second crop after 
the application of the volatile antiseptics. This, however, was in all 
cases less marked than with tlie first cropping. Both types of soils re- 
sponded to treatment, but somewhat differently. 

3. The volatile antiseptics experimented with had a definite effect 
upon tlie ammonification and nitrification of the soil, enhancing the for- 
mer and inhibiting the latter. There is a tendency for the volatile anti- 
septics to increase the water-soluble salts of the soil. 

4. The effect of the antiseptics upon the ammonifying and nitrifying 
processes of the soils after two crops were grown seems to disappear. 

5. No marked differences were observed as to plant growth and bio- 
logical activity between the saturation and extraction methods of apply- 
ing the volatile antiseptics to the soil. 

6. In these experiments the physical condition of the soil as indicated 
by its ammonification and nitrification does not seem to be the cause 
of the influences noted upon plant growth and bacterial action. 

7. By tlie extraction of soil with alcohol, a substance was removed 
which was toxic in water cultures but not at all toxic when in the soil 
itself. 

8. The development of acids in the soil as a result of some action or 
change of the alcohol was found to be too slight to account for the 
marked effects of volatile antiseptics upon plant growth and bacterial 
action. 

Final Conclusions 

The beneficial influences obtained by treating the soil with volatile 
antiseptics can not be ascribed to a change in physical condition, to a 
suppression of some toxic material, or to a development of acids from 
the action of the antiseptics. The method of applying the antiseptics 
seems to have no marked influence upon the results obtained. 

The closely coordinated stimulation of plant and bacterial activity 
due to the treatment of the soil with volatile antiseptics points strongly 
towards a biological interpretation, with due regard for the chemical 
considerations, of the effects therefrom. 

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DU BUISSON-EFFECT OF VOLATILE ANTISEPTICS 389 

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1911. A contribution to our knowledge of the protozoa of the soil. In 
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1911. The bacterio-toxins and the agricere of soils In Centl)l. Bakt. 

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(19) HiLTNtU*, L. 

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390 SOIL SCIENCE 

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PLATE I 

The effect of alcohol and gasoline treatments of Dunkirk clay loam on the growth 

of oats at the blooming stage. 

(For data see Table III.) 



Du P.iiissnii— l-tlr.i ni \,,laiil. AiniMi.ti 



^n 



J:=^ 










/rv 




. ■' '} 




^14^ 







IV-;. - 



oil Scii-iHc 



\(il. Ill, No. A 



Du Bui-isnn— KfffCt (if \nl;itilr AntiMi.ti.-- 



DLL. 

till i Ciilc d 




Alcohol Saturn led 1 \lcoh>! tZxtracted 



Fig. 1 





^ |i(«j«iis«|| ^^wK-o"! JVwiWito- 



DCL. DLL. I DLL. 

Unii^aicd j Ether Saturated j| Ether Extracted 



\.il. III. Xu 4 



PLATE II 

The effect of alcohol and ether treatments of Dunkirk clay loam soil on the growth 

of oats just before heading. 

(For data see Table V.) 



LIBRflRY OF CONGRESS 



llllllllll'illll'll lil!'ll!''ll'i illlilll" "W 

002 603 498 3 • 



